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Purpose: To evaluate a silent MR active catheter tracking sequence that allows conducting catheter interventions with low acoustic noise levels. Methods: To reduce the acoustic noise associated with MR catheter tracking, we implemented a technique previously used in conventional MRI. The gradient waveforms are modified to reduce the sound pressure level (SPL) and avoid acoustic resonances of the MRI system. The efficacy of the noise reduction was assessed by software‐predicted SPL and verified by measurements. Furthermore, the quality of the catheter tracking signal was assessed in a phantom experiment and during interventional cardiovascular MRI sessions targeted at isthmus‐related flutter ablation. Results: The maximum measured SPL in the scanner room was 104 dB(A) for real‐time imaging, and 88 dB(A) and 69 dB(A) for conventional and silent tracking, respectively. The SPL measured at different positions in the MR suite using silent tracking were 65–69 dB(A), and thus within the range of a normal conversation. Equivalent signal quality and tracking accuracy were obtained using the silent variant of the catheter tracking sequence. Conclusion: Our results indicate that silent MR catheter tracking capabilities are identical to conventional catheter tracking. The achieved acoustic noise reduction comes at no penalty in terms of tracking quality or temporal resolution, improves comfort and safety, and can overcome the need for MR‐compatible communication equipment and background noise suppression during the actual interventional procedure. [ABSTRACT FROM AUTHOR]

Introduction: Thermal injury during radiofrequency ablation (RFA) of atrial fibrillation (AF) can lead to pulmonary vein stenosis (PVS). The aim of the present study was to analyze the natural course of RFA‐induced PVS with regard to the grade of stenosis, clinical symptoms, and mortality during long‐term follow‐up. Methods and Results: All patients with follow‐up imaging for radiofrequency‐induced untreated PVS were retrospectively assessed. From 2004 to 2017, the total rate of PVS following AF ablation in our center was 0.78% (87 of 11 103). Thirty‐eight patients with a total of 54 untreated PVS underwent follow‐up including imaging scan. The mean degree of stenosis at the time of diagnosis was 57% ± 27% vs 45% ± 35% (P = .05) after a mean follow‐up of 43 ± 31 months. There was a shift in severity of the PVS: 18 of 54 (33%) vs 16 of 54 (30%) severe PVS, 19 of 54 (35%) vs 10 of 54 (18%) moderate PVS, and 17 of 54 (32%) vs 28 of 54 (52%) mild PVS (P = .0001). The mean symptom score decreased significantly during follow‐up (1.8 ± 1.0 vs 0.4 ± 0.5, P = .0001). Each of the four patients with progression of PVS underwent another pulmonary vein isolation for AF recurrence following pulmonary vein reconduction during follow‐up period. Conclusion: This study showed a spontaneous reduction in stenosis grade and symptoms of PVS over a 3.5‐year follow‐up. Consequently, routine follow‐up imaging of PVS seems not to be necessary. However, additional RF energy delivery to stenotic pulmonary veins should be avoided if possible. In case of conduction recovery, the ablation line should be done wide‐antrally and follow‐up imaging of PVS is recommended. [ABSTRACT FROM AUTHOR]

Background The most likely origin of premature ventricular contractions (PVCs) may be deduced from surface electrocardiogram (ECG) analysis while planning an electrophysiological study (EPS). Apart from purely benign forms of increased ventricular ectopy, myocardial substrate (e.g., regional fibrosis) may be present in certain cases, which will significantly impact the ablation approach. Cardiac magnetic resonance (CMR) imaging can reliably identify fibrotic target lesions and, hence, may assist in adequate patient selection and procedural planning. Methods and results We analyzed 101 patients (59% males, mean age 57.15 ± 15.5 years, mean PVC count 19,801 ± 14,021 per 24 hours) referred for ablation of PVCs. The CMR (1.5T, Philips Ingenia, Best, The Netherlands) protocol included cine and three-dimensional-delayed enhancement imaging using standard cardiac geometries. On surface, ECG right bundle branch block (RBBB) morphology was present in 43% of patients. Twenty-one patients showed the fibrotic substrate on CMR. On univariate analysis, both RBBB morphology (P < 0.001) and presence of multiple PVC morphologies (≥2) significantly predicted the presence of fibrotic substrate (P = 0.01), which various baseline characteristics including left ventricular ejection fraction (45.7 ± 12.6% vs. 50.6 ± 11.0%, P = 0.08) failed to do. CMR-identified fibrosis was associated with the site of origin of the clinical PVCs during EPS and was successfully treated by radiofrequency ablation in 93% (PVC reduction >95%). Conclusion In patients with RBBB morphology and/or multiple PVC patterns, CMR imaging before ablation may be helpful due to the increased prevalence of fibrotic lesions with regard to patient stratification and periprocedural management. [ABSTRACT FROM AUTHOR]

Key Clinical Message: This case emphasizes the value of cardiac MRI and genetic testing in the early phase of ARVD/C. It also emphasizes the increased risk of SCD for patients with ARVD/C participating in competitive sports, even with immediate cardiopulmonary resuscitation. This case emphasizes the value of cardiac MRI and genetic testing in the early phase of ARVD/C. It also emphasizes the increased risk of SCD for patients with ARVD/C participating in competitive sports, even with immediate cardiopulmonary resuscitation. [ABSTRACT FROM AUTHOR]

Purpose: [ABSTRACT FROM AUTHOR]

Background: Quantitative analysis of left-ventricular (LV) aneurysms after myocardial infarction is prognostically relevant and assists in planning surgery. Three-dimensional (3D) echocardiography facilitates clear visualization of cardiac anatomy and accurate assessment of functional parameters. The aim of the present study was to determine the ability of 3D echocardiography to quantify LV aneurysms. Methods: Ten patients with a known LV-aneurysm after myocardial infarction underwent 3D echocardiography and cardiac magnetic resonance (CMR) imaging at 1.5 Tesla within 3 days. For 3D echocardiography, a multiplanar transesophageal examination was performed with full LV coverage and the 3D dataset was analyzed offline. The LV-aneurysm was defined by a wall thickness <5 mm. The following quantitative parameters were determined: left ventricular end-diastolic and end-systolic volumes, LV myocardial mass (LV-mass) and mass of the LV-aneurysm. LV ejection fraction and percentage of aneurysm mass (%-aneurysm) were calculated. Results: LV volumes and ejection fraction showed a strong correlation between 3D echocardiography and CMR (r = 0.94–0.97; P < 0.01). Importantly, the mass and percentage of mass of the LV-aneurysm demonstrated a high correlation as well (r = 0.94 and r = 0.86, respectively; P < 0.01). For all parameters, the calculated bias between both methods was found to be minimal (0.8–7.6%). Conclusions: Three-dimensional echocardiography proved to be a reliable tool for quantitative analysis of LV volumes, ejection fraction and aneurysm size in patients with prior myocardial infarction. In addition, 3D visualization of the complex cardiac anatomy in patients with LV-aneurysm may assist surgical procedure planning. (Echocardiography 2010;27:64-68) [ABSTRACT FROM AUTHOR]

Purpose To evaluate the influence of heart rate variability on image quality in patients with suspected coronary artery disease during magnetic resonance coronary angiography (MRCA). Materials and Methods The coronary images from 70 patients who underwent target-volume MRA were retrospectively analyzed. Two independent observers evaluated image quality using a score from 0 (nonvisible) to 4 (excellent quality). Images were grouped into good (score > 2) and poor image quality (score 0-2). Five parameters (effective scan duration, navigator efficiency, mean heart rate, acquisition window, and heart rate variability) were evaluated. Results In all, 56 of the 70 patients (80%) were scored as good and 14 as poor image quality. Only the navigator efficiency, heart rate variability, and acquisition window showed statistically significant for the prediction of image quality, with navigator efficiency being the strongest predictor. Subgroup analysis showed that patients with navigator efficiency >60% had good image quality independent of the heart rate variability. In patients with navigator efficiency ≤60%, heart rate variability is the only remaining significant parameter ( P = 0.03). Conclusion Navigator efficiency was the most important predictor of MRCA image quality. Heart rate variability is the most important predictor of image quality in patients with a navigator efficiency ≤60%. J. Magn. Reson. Imaging 2008;28:74-79. © 2008 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the impact of a new, cross-correlation based method for compensation of respiratory induced motion of the heart using an individually adapted three-dimensional (3D) translation or affine transformation approach. Materials and Methods A total of 32 patients underwent a routine cardiac MR examination. In each patient, a calibration scan was performed during free-breathing to register breathing-related motion within a 3D ellipsoid registration kernel covering the entire heart. Three navigators were employed for all three spatial dimensions (feet-head, anterior-posterior, and left-right) and the optimal translatory correction factors for each spatial dimension were determined. In addition, the cross-correlations for different motion models (no compensation, fixed 1D-translation, adapted 3D-translation, and affine transformation) were calculated. Results The mean correction factor for the feet-head direction was 0.45 ± 0.13. Though the mean correction factors for the anterior-posterior and left-right direction were nearly zero (-0.01 ± 0.08 and 0.02 ± 0.09, respectively), the correction factors exceeded the amount of 0.1 in 12 (19%) and in 19 patients (30%), respectively. All motion compensation models showed significantly higher cross-correlations when compared to 'no compensation' ( P < 0.05). In particular, the affine transformation algorithm achieved the highest cross-correlation values (88.3 ± 5.1%) with a significant increase compared to fixed 1D translation (84.7 ± 6.5%, P < 0.05). Conclusion A considerable number of patients demonstrated relevant breathing-related movement of the heart in the anterior-posterior or left-right direction in addition to the predominant breathing-related movement in the feet-head direction. Thus, it is recommended to compensate for all three spatial dimensions. The affine transformation algorithm combined with three navigators significantly improved breathing-related cardiac motion compensation when compared to the conventionally applied 1D translation with a fixed correction factor. J. Magn. Reson. Imaging 2007;26:780-786. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Purpose To prospectively determine the accuracy of four-dimensional (4D) kt-broad-use linear acquisition speed-up technique (BLAST) accelerated MRI (kt-BLAST) for the assessment of left-ventricular (LV) volumes and mass as well as right-ventricular (RV) volumes in comparison to standard multiple breathhold cine imaging. Materials and Methods A total of 40 patients with suspected or known coronary artery disease (CAD) underwent cardiac MRI. In each patient a standard multislice cine steady-state free precession (SSFP) sequence was performed with complete ventricular coverage during multiple breathholds. Additionally, a kt-BLAST-accelerated 4D sequence with complete ventricular coverage was acquired during one single breathhold. For comparison of SSFP and kt-BLAST, the following LV parameters were determined: end-diastolic and end-systolic volumes, ejection fraction, end-diastolic diameter and mass. For comparison of RV dimensions, end-diastolic and end-systolic volumes and ejection fraction were assessed. Results LV volumes, ejection fraction, diameter, and mass showed a strong correlation between SSFP and kt-BLAST (r = 0.98-0.99; P < 0.01). In addition, RV parameters demonstrated a high correlation (r = 0.97-0.98; P < 0.01). For all parameters, the calculated bias between both methods was found to be minimal (0.4-4%). Conclusion 4D kt-BLAST-accelerated MRI enabled the accurate assessment of LV and RV quantitative parameters during one single breathhold when compared to standard multislice, multiple breathhold SSFP imaging. J. Magn. Reson. Imaging 2007. © 2007 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]